Combined food and wipe heater

ABSTRACT

A combination heater device including an inner pouch with an activation agent and an outer pouch with a heat generating material adapted to generate heat upon contact by the activation agent. A first package containing at least one wipe is in heat absorbing contact with the heater as is a second package containing a food element requiring heating. A package holding element maintains the first and second package in contact with the heater.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of Heater Device applicationfiled Jul. 22, 2008, having Ser. No. 12/220,146, which is acontinuation-in-part of Pan In Pan Heater application filed Oct. 4,2007, having Ser. No. 11/973,178.

BACKGROUND

This invention relates to a device for heating the contents of acontainer and for keeping it warm. More particularly, the inventionrelates to a self-contained heater device that allows the contents suchas food in a container to be heated.

Often times, it is desirable to heat food and other items at a locationremote from a source of heat such as a stove or oven. Other times it isdesirable to take warmed or hot food and other items from the place ofheating to another location, such as a picnic, school or churchbasement, scout meeting and any of the myriad of events that do not meetor gather where heat is available. Sometimes the location is in alocation where fire is not permitted, such as a class room or outdoorsduring the dry season. It is also important for military personnel tohave access to warm food, particularly when deployed in locations remotefrom their base or station.

One such self-contained warmer is disclosed in U.S. Patent ApplicationPublication No. US 2007/0034202, to Punphrey et al. in which a containerwith an exothermic composition is used to heat a vessel. A membrane isused to cover the exothermic composition, which is then activated byremoval of the membrane. Various compositions are disclosed that arebased on iron oxidation chemistry. The heater is in direct contact withthe container and must be put on a heat-resistant surface to be usedwithout damage.

U.S. Pat. No. 6,705,309 discloses a self-heating or self-coolingcontainer in which tubular walls defining an internal cavity into whichsteam or hot air is placed as a source of heat. This, of course,requires a source of that heated material.

Other heater devices for food generate heat by chemical reaction, and inso doing generate hot gases, steam or hot water vapor, which ispotentially hazardous to the user and which may, in some instances,contribute to pollution of the environment.

It would be a great advantage if a way of heating containers could bedeveloped that have a controlled release of heat that is withinacceptable safety limits.

Another advantage would be to provide a way of heating containers thatproduces heat over an extended period of time, rather than simply havingan exothermic reaction that lasts a few minutes or less.

Yet another advantage would be to provide a way to generate heat by anexothermic reaction without releasing any gas, steam or hot water vaporto outside the device.

Also, often when someone is in a remote location, such as camping or thelike, there is not a convenient facility for cleaning up one's self orone's equipment such as eating utensils and the like. It would be ofgreat advantage if the food and the means to clean up after cookingcould be combined into one product.

Other advantages will appear hereinafter.

SUMMARY

The unique aspect of this invention is that a controlled, dispersedexothermic reaction can be used to heat or cook the contents of acontainer quickly and effectively while maintaining the heat for anextended period of time without releasing any of the reaction productsto outside of the device. Also included in the product is a quantity ofpersonal hygiene wipes or towels that can be used to clean up aftercooking or eating. The combination in one package provides excellentconvenience.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of one component of this invention.

FIG. 2 is a perspective view of the preferred embodiment prior toassembly.

FIG. 3 is a side view of the embodiment of FIG. 2 after assembly.

DETAILED DESCRIPTION

In its simplest form, the present invention is a combination of aself-contained heater, a food package, and some wipes or towels, all inone package at the time of use. By the term “wipe” is meant any objectsuch as a personal hygiene wipe, tissue, towel, handkerchief, wash clothor other object used as a cleaning device, such as to cleanse silverwareor one's hands. The food package may be any package containingcomestibles or other material that is to be heated. Typical food boxesare what is known in the military as MRE, which is an acronym for “mealsready to eat.” The heater is activated by causing an activation agent inan inner pouch to transfer to an outer pouch that contains heatgenerating materials. Because the outer pouch is sealed, vapor or otherbyproducts of the reaction are kept inside and do not affect the user.

It is desirable to provide more than one personal hygiene wipe. Anypractical number of wipes is contemplated by this invention, for exampleand not by way of limitation, packs of three or five or more, and theinvention is not limited to any number of wipes. Preferred are thosewipes made of spun lace fabric, such as those from rayon and polyesterfibers

The preferred heater is described in a commonly owned co-pending U.S.Patent Application having Ser. No. 11/584,145, filed Oct. 20, 2006, thedisclosure of which is incorporated herein in its entirety. The heaterof this application features an inner pouch with an activation agenttherein, an outer pouch with a heat generating agent and a vacuumtherein, such that the vacuum assists in transferring the activationagent into intimate contact with the heat generating agent rapidly andthoroughly.

The use of a heater of this type with food packages is described in acommonly owned co-pending U.S. Patent Application having Ser. No.12/220,146, filed Jul. 22, 2008, the disclosure of which is incorporatedherein in its entirety. The various activation devices used to break theseal between the inner and outer pouch are also examples of the meansfor activating the present invention.

As seen in FIG. 3, a food package 11 and a wipe pouch 13 are on eachside of heater 17. Heater 17 is shown in FIG. 1 as having an outer pouch19 with heat generating material 21 inside it. Inner pouch 23 includesan activation agent 25 inside it. Pouch 23 also has a seal 27 which, inthis embodiment is a rigid plastic piece 27 with a score line 29.Flexing pouch 23 at seal 27 causes score 29 to split open, allowing theactivation agent 25 to flow into pouch 19. Other seals are alsocontemplated, including those described in a commonly owned co-pendingU.S. Patent Application having Ser. No. 12/152,013, filed May 12, 2008,the disclosure of which is incorporated herein in its entirety.

Pouch 19 preferably has a vacuum inside it, most preferably ranging fromabout 9 psi to about 13 psi. Alternatively, pouch 23 can have anelevated pressure of from about 15 to 19 psi.

In FIG. 2, the packages 11 and 13 are shown separated from the heater17. In FIG. 3, the product has been assembled and a package holdingelement 31 holds them together. Alternatively, the elements can beattached to the pouch via an adhesive or simply placed together on atable or other surface.

Preferred is an outer pouch made from Aclar®, which is apolychlorotrifluoroethylene (PCTFE) material manufactured and sold byHoneywell International Inc. Aclar film is crystal clear, biochemicallyinert, chemical-resistant, nonflammable, and plasticizer- andstabilizer-free. Aclar laminates provide a wide range of gauges and thusbarrier levels to allow flexibility in selecting the optimum barrierlevel for the chemical system chosen. Other similar pouch materials maybe used as well. All that is required is that the material have afunctional moisture and vapor barrier for the other components of theinvention.

In a preferred embodiment, inner pouch is made from a heat stamp foilthat is moisture impervious. In a preferred embodiment, the foil pouchincludes a rigid portion with a score line adapted to rupture whenflexed to empty the activation agent into the outer pouch

There are a number of combinations of heat generating materials andactivating agents that are suitable for use in the present invention.The selection of specific components is to be based upon cost,compatibility, ease of control of the exotherm, and other factors.

The preferred activating material of this invention is water. This isplentiful and safe, and reacts with a number of materials to produce anexothermic reaction.

The preferred heat generating material is a solid formed from severalcomponents that, when free from moisture, are stable for up to three tofive years or more, and which react when moisture is present to generateheat. The preferred solid is made from crystalline calcium oxide, azeolite powder, and a polyalkyl glycol such as polyethylene glycol. Theamount of activation material, such as water, is preferably from about75 to 125 weight percent, based upon the total weight of heat generatingmaterial. Approximately equal amounts by weight of water and heatgenerating material is the preferred ratio.

The amount of calcium oxide ranges from about 30 to 70 weight percent,the amount of polyethylene glycol ranges from about 15 to about 35weight percent, and the amount of zeolite ranges from about 15 to about35 weight percent, based on the total weight of heat generatingmaterial. Preferred is about 25 weight percent each of the polyethyleneglycol and zeolite and about 50 weight percent calcium oxide

The heat generation material most preferred, using the above componentsincludes a calcined calcium oxide. This material is available as a smallparticle size, with a diameter less than about 0.2 mm, and as a particleof somewhere between 0.2 and 0.8 mm. Larger particles are ground andsmaller ones sieved, and the calcium oxide is then calcined. It has beenfound to be effective to calcine for at least 60 to 120 minutes, andpreferably about 90 minutes, at temperatures above 500° C., and mostpreferably at about 550° C. for that period of time. The calcinedcalcium oxide is, of course, desiccated to prevent any contamination bymoisture.

More than 150 zeolite types have been synthesized and 48 naturallyoccurring zeolites are known. They are basically hydratedalumino-silicate minerals with an “open” structure that can accommodatea wide variety of positive ions, such as Na+, K+, Ca₂+, Mg₂+and others.These positive ions are rather loosely held and can readily be exchangedfor others in a contact solution. Some of the more common mineralzeolites are: analcime, chabazite, heulandite, natrolite, phillipsite,and stilbite. An example mineral formula is: Na₂Al₂Si₃O₁₀-16H₂O.Zeolites, by their nature, are finely porous structures that are“hungry” for water and that have the ability to hold heat. In thepresent invention, the activation agent, water in the preferredembodiment, enters into the zeolite pores, trapping the water as it isheated by reacting with the calcium oxide, thus storing heat, providinga longer, more evenly distributed supply of useable heat.

The polyethylene glycol component of the heat generating material isadmixed with the calcium oxide and zeolite and placed in the outercontainer as described above. When the activation agent, water, isintroduced into the heat generating material, the polyethylene glycolcoats the calcium oxide and zeolite, further delaying the exothermicreaction between calcium oxide and water, and adding to the utility ofthis invention.

The present invention provides a significant advantage over the priorart in several ways. Because the outer container is sealed, as describedabove, the exothermic reaction when heat is generated does not releasesteam or other vapor as do presently available heaters. In addition, theheater device of this invention is much more effective that what hasbeen done in the past. The heater of this invention has been used toheat products to 150° F. within 5 minutes and maintained the heat at orabove 140° F. for 50 minutes. Prior art devices take 12 minutes to reachonly 140° F. and only hold that temperature for 20 minutes. Thus thefood can be cooked and kept warm for more than enough time to consumeit. In addition, the wipes are kept warm in the same manner.

Also, because there is a vacuum in the pouch containing the heatgenerating material, breaking the seal causes the activating agent topour into contact throughout the container, resulting in proper heatgeneration. In a series of tests of this embodiment, 100% of theactivations resulted in warm personal hygiene wipes. Then a similar setof packages were prepared, with the only change being no vacuum insidethe outer pouch, only 30% of the wipes achieved the desired temperature.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

1. A combination heater device, comprising: a heater having a first sidefor transferring heat and a second side for transferring heat, includingan inner pouch with an activation agent and an outer pouch with a heatgenerating material adapted to generate heat upon contact by theactivation agent, and further including a seal for selectively openingthe inner pouch to permit a heat generating reaction; a first package inheat absorbing contact with the first side of the heater and includingat least one wipe, the first package having opening to provide access tothe at least one wipe; and a second package in heat absorbing contactwith the second side of the heater and including at least one foodelement requiring heat to prepare for consumption.
 2. The device ofclaim 1 which further includes a package holding element maintaining thefirst and second package in contact with the heater.
 3. The device ofclaim 1, wherein a pressure differential is formed between the pressurein the outer pouch and the inner pouch such that the inner pouch has ahigher pressure than the outer pouch, whereby, upon opening the innerpouch, the activation agent is driven into the outer pouch to react withthe heat generating material.
 4. The device of claim 3, wherein thepressure differential is caused by a vacuum inside the outer pouch. 5.The device of claim 1, wherein the actuation agent is water and the heatgenerating material is crystalline calcium oxide.
 6. The device of claim5, which further includes powdered zeolite admixed therein with thecalcium oxide.
 7. The device of claim 6, which further containspolyethylene glycol admixed with the calcium oxide and powdered zeolite.8. The device of claim 7, wherein the amount of calcium oxide rangesfrom about 30 to about 70 weight percent, the amount of polyethyleneglycol ranges from about 15 to about 35 weight percent, and the amountof zeolite ranges from about 15 to about 35 weight percent, based on thetotal weight of heat generating material.
 9. The device of claim 8,wherein the amount of water ranges from about 75 to about 125 weightpercent, based on the total weight of heat generating material,
 10. Thedevice of claim 1, wherein the first package contains from 3 to 5 wipes.11. The device of claim 10, wherein the second package is a MRE.
 12. Thedevice of claim 1, wherein the outer pouch forms the first and secondsides for transferring heat to the first and second packages.
 13. Thedevice of claim 1, wherein the outer pouch is formed from a vaporimpervious material.
 14. The device of claim 12, wherein the inner pouchis formed from a foil material having a rigid portion with a score lineadapted to rupture when flexed to empty the activation agent into theouter pouch.
 15. A combination heater device, comprising: a heaterhaving a first side for transferring heat and a second side fortransferring heat, including an inner pouch formed from a foil materialand containing an activation agent and an outer pouch with a heatgenerating material comprising calcium oxide ranges from about 30 toabout 70 weight percent, the amount of polyethylene glycol ranges fromabout 15 to about 35 weight percent, and the amount of zeolite rangesfrom about 15 to about 35 weight percent, based on the total weight ofheat generating material, the activation agent comprising water in anamount ranging from about 75 to 125 weight percent, based on the totalweight of heat generating material, the heater further including a sealfor selectively opening the inner pouch to permit a heat generatingreaction; a first package in heat absorbing contact with the first sideof the heater and including at least one wipe, the first package havingopening to provide access to the at least one wipe; and a second packagein heat absorbing contact with the second side of the heater andincluding at least one food element requiring heat to prepare forconsumption.
 16. The device of claim 15, with further includes a packageholding element maintaining the first and second package in contact withthe heater.
 17. The device of claim 15, wherein a pressure differentialis formed between the pressure in the outer pouch and the inner pouchsuch that the inner pouch has a higher pressure than the outer pouch,whereby, upon opening the inner pouch, the activation agent is driveninto the outer pouch to react with the heat generating material.
 18. Thedevice of claim 17, wherein the pressure differential is caused by avacuum inside the outer pouch.
 19. The device of claim 15, wherein thefirst package contains from 3 to 5 wipes.
 20. The device of claim 19,wherein the second package is a MRE.